mole = 78.40/207.2
= 0.379 mol
1 mol = 6.02 × 10^23 atoms
0.379 mol = X
X = 0.379/1 × 6.02 × 10^23
= 6.296 × 10^-25 atoms
Can someone help? Thank you.
that' the answer i don't need an explanation
Which of the following best represents a chemical change?
A. Chopping wood
B. Silver tarnishing (changing color)
C. Grape kool-aid mix dissolving in water
D. Dry ice turning into a gas (sublimation- a change of state)
B. silver tarnishing
What is the mass of an aluminum block if the density of aluminum is 2.70
g/cm and the volume of that block is 4.8 cm?
Answer: 50 M
Explanation:
Mass
Density×Volume2.7(4.8)11.6111.6gFormula used
Density=Mass/VolumeIf the concentration of KMnO4 was 0.0235 M, calculate the number of moles of MnO4- ions that completely reacted with the H2C2O4
The number of moles of KMnO4 is 0.0006 moles.
The equation of the reaction is;
6 H^+(аq) + 2 МnO4^- (аq) + 5 Н2С2O4(аq) → 10 CO2 (g) + 8 H20 (l) + 2 Mn²+ (aq)
We can see that the volume of the titrant used = Final - initial burette reading
= 29.6 mL - 3.4 mL = 26.2 mL
Number of moles of H2C2O4 = 0.139 g/90 g/mol = 0.0015 moles
If 2 moles of MnO4- reacts with 5 moles of H2C2O4
x moles of MnO4- reacts with 0.0015 moles of H2C2O4
x = 2 moles × 0.0015 moles / 5 moles
x = 0.0006 moles
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how do you Calculate the molarity of 250 ml of solution in which 2.7 g of MgCl2 are dissolved
Answer:
Molar mass of MgCl2 is 95 g/mol
Mg = 24 g/mol and Cl = 35.5 ×2 = 71 g/mol
moles = mass given/ molar mass
= 2.7/95 = 0.028 mol
volume = 250/1000 = 0.25 dm3 (ml is the same as dm3)
molarity of MgCl2 = moles/volume
= 0.028/0.25
= 0.112 mol/dm3
As an electron in an atom moves from a higher energy state to a lower energy state, the atom
A
becomes a negative ion
В.
becomes a positive ion
С.
releases energy
D.
absorbs energy
Answer:B
Explanation:
A student reads that sodium atoms (Na) react with chlorine (Cl2) molecules to form the compound sodium chloride (NaCl). Which model should the student make to satisfy the Law of Conservation of Matter for the formation of sodium chloride, in simplest form?
Answer:
c
Explanation:
Law of Conservation of Matter for the formation of sodium chloride, in simplest form would be obeyed when 2 moles of sodium react with 1 ,mole of chlorine to form 2 moles of sodium chloride.
What is law of conservation of matter?According to law of conservation of matter, it is evident that matter is neither created nor destroyed rather it is restored at the end of a chemical reaction .
Law of conservation of matter and energy are related as matter has mass and mass and energy are directly proportional which is indicated by the equation E=mc².Concept of conservation of matter is widely used in field of chemistry, fluid dynamics.
Law needs to be modified in accordance with laws of quantum mechanics under the principle of mass and energy equivalence.This law was proposed by Antoine Lavoisier in the year 1789.
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50 PTS!!!!!
What type of chemical reaction is Aerobic Cellular Respiration?
Answer: During aerobic respiration, catabolic reactions convert larger complex organic molecules into ATP, the chemical that drives most physiological processes in the body.
Explanation:
If 3.5 mols of P2O3 are formed, how many
moles of P4 reacted?
P2 is 3.5 for p4= 2p2 i.e 2*3.5=7
Answer;561gp203 are required to
produce 10.2 mol H3p03
What holds the nucleus together? Group of answer choices alpha particles strong forces electrical forces between the protons beta particles
Answer:electrical forces between the protons
Explanation: The strong nuclear force pulls together protons and neutrons in the nucleus. At very small distances only, such as those inside the nucleus, this strong force overcomes the electromagnetic force, and prevents the electrical repulsion of protons from blowing the nucleus apart.
To calculate the atomic mass of an element, the percent
abundance of etch isotope is needed. ?
Answer:
List the known and unknown quantities and plan the problem. Change each percent abundance into decimal form by dividing by 100. Multiply this value by the atomic mass of that isotope. Add together for each isotope to get the average atomic mass
Explanation:
ghjguygyughyyhghygyuguyg
Determine the frequency of light with a wavelength of 2.672 x 10^-7cm
Answer:
Determine the frequency of light with a wavelength of 2.775⋅10−7 cm. Answer in units of Hz?❤
If the adoms dont work are they dead
Answer: no
Explanation:
Atoms are not and have never been alive so they can't be considered dead. they simply do not meet any reasonable of life, primarily because they are not complex.
What is black powder made of? (Please provide percentage composition of elements as well) Will give brainliest
Answer:
Black powder has 3 main ingredients: Sulfur ([tex]S[/tex]), charcoal ([tex]C_{7}H_{4}O[/tex]), and potassium nitrate ([tex]KNO_{3}[/tex]).
Charcoal is basically just burnt wood and potassium nitrate can easily be displaced.
Keep in mind that this is BLACK POWDER and not actual gunpowder. The difference between the both is significant since gunpowder has a lot more refining processes it has to go through to be actually used in firearms and such.
The percentage composition of black powder should be 75% Potassium Nitrate, 10% Sulfur, and 15% charcoal.
Should be noted that black powder is not a safe compound to deal with, as static friction could ignite it.
There are other alternatives to Black powder such as nitroglycerin (used in dynamites) which is way more powerful and useful in doing mines and exploration but is an extremely tricky and reactive substance to work with.
I do hope this is just for educational purposes because you need to be certified to even just experiment with this (and there are laws to synthesize such as well, which I won't take any responsibility for)
Answer:
sulfur, charcoal and potassium nitrate
Explanation:
Payback
patient requires blood transfusion. what is the next thing to do? discuss
I NEED HELP WItH THIS 5th GRADE QUESTION ITS VERY VERY EASY no Links PLZ and I will Report any useless AWnser PLZ HELP WILL mARK AS BRAINLIST AND Will giVE 1000 Points if correct Answer
How is the mass of a solid measured?
By estimating
With a beaker
With a ruler
With a scale
Answer:
A Beaker or graduated cylinder
Explanation:
Place the solid into the graduated cylinder. Measure the amount of water in the graduated cylinder. The product is the solid's mass wich i mean by that is what number the water level is at.
Answer:
Beaker
Explanation:
It takes 120 mL of 0.15 M of carbonic acid (H2CO3) to neutralize 300 mL of sodium hydroxide (NaOH) for the following balanced chemical reaction:
2NaOH + H2CO3 → N2CO3 + 2NaOH
The concentration of the sodium hydroxide _____.
An aqueous solution was prepared by dissolving 266.07 g of AgNO3 ( 169.88 g/mol) in enough water to make a total volume of 250.0 ml. What is the molarity of the solution
Answer:
The correct answer is 6.265 M.
Explanation:
To find the molarity of the solution, we first must recall that molarity represents the number of moles of solute divided by the number of liters of solution. Thus, our first step should be to convert the solute amount in grams to moles, using the given molar mass.
266.07 g * (1 mol/169.88 g) = 1.5662 mol
Now, we can find the molarity using the following formula:
Molarity = moles solute/liters solution
M = 1.5662 mol/0.25 L
M = 6.265 M
Therefore, the molarity of the solution is 6.265 M.
Hope this helps!
need help with question please ..
-20 points
Answer:
B oklolol
[tex][tex]\purple{\rule{45pt}{7pt}}\purple{\rule{45pt}{999999pt}}[tex][/tex]
what is the chemistry of super glue
cyanoacrylate
When cyanoacrylate polymerizes, the cyanoacrylate sticks together on an atomic level, and it becomes solid. Super Glue solidifies in all the microscopic crevices of an object that it moved into when it was a liquid, and it can form chemical bonds with any anions in the object.
How many grams of N2 are required to react with 4.2 moles of Mg in the following process?
3 Mg + N2 → Mg3N2? (Mg = 24.3 g/mol, N = 14.0 g/mol)
Answer:
x = 0.45*28/3 = 4.2 g
Explanation:
showing work
N2 = 28 g/mole
3Mg + N2 → Mg3N2
3moles .. 28 g
0.45 moles .. x
x = 0.45*28/3 = 4.2 g (answer)
9 Select the correct answer. Which statement correctly describes a physical change? O A involves breaking and creating chemical bonds but not changing a phase OB. may involve a change in phase but does not involve a change in the molecular structure OC. may involve converting two or more substances into new substances OD. involves changes at the molecular level O E. involves energy transfer and change in color Reset Next
Answer: The statement that correctly describes a physical change is may involve a change in phase but does not involve a change in the molecular structure. The answer is letter B.
Explanation: trust me
Explanation:
OA- because there is breakdown of chemical bonds
Which is better Epoxy or Super Glue?
Answer:
Personally, I use Superglue
Explanation:
Can someone help me with this please
Answer:
1.
a. Diagram A
b. Diagram A should stay still, but Diagram B should move/roll to the left.
__________________________________
2.
a. Diagram A and Diagram B are different because the object kg are different, one is 10kg and the other is 2kg.
b. Diagram B because its smaller making it lighter to move when Diagram A is 5 times larger, which will make it heavier.
__________________________________
3.
a. Diagram A and Diagram B compare because the object both equal 3kg.
b. Diagram A will have a greater acceleration because 80n > 40n
Describe echolocation. Give an example of an animal that uses echolocation.
dolphin and whales use echolocation
10 ml of solution of acetic acid is added to 250 ml volumetric flask , the concentration of diluted vinegar is 0.01 M. What is the % by mass of acetic acid in vinegar if the density of vinegar is 1.05 g/ml. ( C: 12 O:16 H: 1 )
The percentage by mass of the acetic acid is 0.057%.
The given parameters:
Volume of the acetic acid = 10 mlVolume of the flask, = 250 mlConcentration of the diluted vinegar = 0.01 MDensity of the vinegar, ρ = 1.05 g/mlThe concentration of the acetic acid is calculated as follows;
[tex]C_1V_1 = C_2 V_2\\\\C_1 = \frac{ C_2 V_2}{V_1} \\\\C_1 = \frac{0.01 \times 250}{10} \\\\C_1 = 0.25 \ M[/tex]
The number of moles of acetic acid in the given concentration;
[tex]C = \frac{mol}{L} \\\\mole = CL\\\\mole = 0.25 \times 10 \times 10^{-3} \\\\mole = 0.0025[/tex]
The molar mass of acetic acid = 60 g/mol
The mass of acetic acid in the given number of moles is calculated as follows;
m = conc. x molar mass
m = 0.0025 x 60
m = 0.15 g
The mass of vinegar in the volume and density;
m = density x volume
m = 1.05 x 250
m = 262.5 g
The percentage by mass of the acetic acid is calculated as follows;
[tex]= \frac{0.15}{262.5} \times 100\%\\\\= 0.057 \%[/tex]
Thus, the percentage by mass of the acetic acid is 0.057%.
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(Please someone help me!) (No links!)
Please ignore the blue dot, I accidentally pressed it and won't get rid of it!
Answer:
you picked the right one the net worth of force would be 10
Explanation:
how cuz you got 1 team with 6 force then aother 1 with 4 add em up u get 10
When the radiation isn't quite strong
enough to kill right away a terrible
Condition follows what is it called
and what is happening.
A sample of CO2 gas at 100 degrees Celsius has a volume of 250 mL at 760 mm Hg. How many moles of CO2 are present
There are 8.16 × 10-³ moles of CO2 gas at 100°C with a volume of 250 mL at 760 mm Hg.
HOW TO CALCULATE NUMBER OF MOLES:
The number of moles of a sample of gas can be calculated using the following formula:
PV = nRT
Where;
P = pressure of gas (atm)V = volume (L)n = number of moles (mol)R = gas law constant (0.0821 Latm/molK)T = temperature (K)According to this question;
P = 760mmHg = 1 atmT = 100°C = 100 + 273 = 373KV = 250mL = 0.250Ln = ?1 × 0.250 = n × 0.0821 × 373
0.250 = 30.62n
n = 0.250 ÷ 30.62
n = 8.16 × 10-³mol
Therefore, there are 8.16 × 10-³ moles of CO2 gas at 100°C with a volume of 250 mL at 760 mm Hg.
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